According to New Scientist, that could be either an encrypted password or a secret question. The decryption key would be stored on the computer or smartphone synched to the charger, meaning that the stored security information would be readable only on the owner's device.

Meanwhile, the device would remain locked to anyone who didn't have the password – or the charger on which it was stored.

The advantage, Apple explains, is that users will be more willing to set passwords if they know there is a easy and reliable way of recovering them. According to the company, often people turn off the secure log-in option, or choose easy-to-guess passwords, because they fear they will forget their log-in details. If the device gets stolen, it is then simple for the thief to use it.

The obvious snag is that once thieves become aware that power adapters contain security information, they'll start stealing them too. That's not too much of a concern in the case of iPods or iPads, Forbes pointed out, since people using them in a public setting are less likely to carry the charger with them. And there may come a time when laptops, too, need charging "so infrequently that power adapters are never taken out the security of a user's home," Forbes said.

Furthermore, Apple suggests in the patent that other peripherals could be made into data stores, allowing security information to be split between several locations:

"For example, a power adapter can store the system login credentials, a docking station can store file system encryption data, a home network router can store a keychain, and so forth. [...] A thief who steals the system while the user is "out and about" would not have at his disposal these peripherals to assist in recovering these stored passwords and credentials."